A conventional battery module is disclosed in JP 2010-97722 A. The battery module includes a cell unit including a plurality of battery cells arranged in a first direction, a positive external terminal electrically connected to a positive side of the plurality of battery cells through a positive electro conductive member, and a negative external terminal electrically connected to a negative side of the plurality of battery cells through a negative electro conductive member.
The above cell unit has a cell terminal surface on which terminals of the battery cells are respectively located. On the cell electro surface, the positive electro conductive member and negative electro conductive member are respectively connected to the positive external terminal and negative external terminal.
In the above conventional battery module, the positive electro conductive member and negative electro conductive member are positioned on the same cell terminal surface of the cell unit. This causes short circuit between the positive electro conductive member and negative electro conductive member when the cell unit is crushed due to external impact or when a metal part around the cell unit contacts both of the positive electro conductive members and negative electro conductive members in a bridging manner.